METALLURGY OF IRON AND STEEL.
1000 pounds;.on the other hand, there were 281 cases where the 2-inch test showed greater strength, and the differences are more marked, the largest group showing an increase of from 1000 to 2000. pounds. ,It w$l be .shown by Table XVI-L that the width of the piece has little 'effect upon'the strength, so that these records give, evidence of the reinforcement of the 2-inch test,from the •shoulders at the ends. , ' . ^
SEC. XIVII—-The pfBliminar^:test-piece.r—GTaiitiD.g that "the test is to !be made on a parallel-sided piece, it has been proposed that the steel be tested by making a trial bar, either round or flat, .rolled from-a small ingot. "It is the custom at Steeltoh to make
r . . . . s. TABLE XVI-H. ,
Comparison of Angles, with'the Preliminary Test. •• •
« DO . .-* II ' ' 00 ; •],;
History of test-piece. 1 - "JO . ri/pt »P< rt^.-
o a> |--- III. pP*H d i* Is Beducti per ce
Cut from ^-inch and f-inch angles „ . . . Rolled from 6-inch, test ingot . '..... 89 89 41800 42270 60190 60200 28.89 26.44 68.0 42.4
Cut from /o-ihch and jHn°h angles . . . . Rolled from 6-lnch test ingot . ..... .46 46 '40170 48070 60660 61860 29.05 26.01 66.4 40.0'
Cut from A-inch and f-inch angles .... Railed from 0-inch test ingot ........ 87 87 89710 42900 61520 62980 28.96' 28.10 68.6 88.2
such a preliminary: test, but this is idone merely to classify: the metal. If the bar is rolled under proper 'conditions, its ultimate, strength represents the ultimate; strength of the finished material, land; without regard to any results on elongaiion or other qualifies, the steel is used or laid aside, but these'records have nothing to ;db"with the acceptance! 05 rejection of the material. ''In other iwbr^s, this,test :is bur .own; work,' .while the inspector is to test ^the material that he; buys, as fully as he may wish, without regaxd -''to whether a small test ingot'has or has not fulfilled certain re-rqiirements'.; | . ; - | ' . : '?? ; •
Table XVI-H compares! tike data obtained from a large number .of charges of ;acid"6pen-h|eafth steel having a tensile, strength be-•tween 56,000 and 64,000 ipqunds per square inch. ''-They were jll